Process of and means for recovering silver from photographic and other baths



N. B. AUKERMAN. PROCESS OF AND MEANS FOR RECOVERING SILVER FROMPHOTOGRAPH IC AND OTHER BATHS'. 'APPLICATION FILED MAY 31. 1919.

Patented Aug. 15, 1922.

ATT 5T INVENTOR' mafia zzMa MMM sides thereof and the NATHANIEL r.AUKERMAN, or mnwoon; orno.

rnocnss or AND MEANS ron RECOVEBING snivnn ornnn Barns.

rnom rnoroemirrc'ann Specification of Letters Patent. Patentd Aug. 15,1922.

Application filed May 31, 1919. Serial 1N0. 300,891.

To all whom. it may concern:

Be it known that I, NjATHANIEL B. AUKER- MAN, a citizen of the UnitedStates, and a resident of Lakewood, in the county of Cuyahoga and Stateof Ohio, have invented a new and useful Process of and Means forRecovering Silver from Photographic and Other Baths.

I believe myself to be the first and original inventor of a galvanic orelectro-chemical method for recovering silver from solutions of thisgeneral character, and the means for which comprises copper and zincelements partially insulated from each other and related as herein shownand described so as to set up within the complete unit anelectro-chemical action, causing not bnly the precipitation of thesilver, but also causing it to be deposited or plated on the Wall of theunit or device in such a pure and compact mass that the silver recoveredis nearly.

of a pure bullion standard. I

It is estimated that from five to seven tons of silver pass through thesewers in the United States alone each month and is lost for the obviousreason that no successful or practical means for the recovery thereof isknown, and which I can reclaim by my simple and inexpensive processWithout special care, time or trouble and which requires no appreciableextra space in the baths. Thus this loss can be turned to profit and thesilver supply of the country correspondingly conserved. In theaccompanying drawings Fig. 1 discloses a perspective view of a partiallyassembled unit or device embodying my invention, and with one of theouter or wooden binding screws therein at the right of the centralfigure and a sheet of blotting paper, or its equivalent, at the left.

Fig. 2 is a perspective view of the device complete and ready. for use,and Fig. 3 is a perspective view of a bath or cell broken awayat oneside and disclosing one of my units or devices therein. As many moresuch units may be added as required for any given size of bath, andwhich maybe connected or used separately as desired.

In the device as thus illustrated A and E,

respectively, show wall pieces of wood or othersuitable non-metallicmaterial of a size, say 3"x 10" but which may be of bath and the silverrecovered by any suit-able size according to the size of the ath orreceptacle.

B shows sheets of copper like those used by photo engravers and forwhich purpose scrap copper may be employed, but I am not limlted tocopper as other material such as Iron, brass, and the like are found tobe of near equal value.

C s ows sheets or layers of zinc and which are shown as the same widthand thickness as the copper but shorter and interposed between thecopper piles on the sides. Zinc chips or filings may be used instead ofsheets. v

F shows strips of blotting paper, wood or other porous material whichabsorb sufiic 1ent moisture to make good galvanic action in the bathsolution and are used to separate each plate or layer of copper andzinc, respectively. A single sheet of these strips is shown to beslightly narrower and shorter to allow the copper elements to besufliciently exposed in the solution to create the properelectro-chemical action and said sheets are formed with a notch orrecess n in each end corresponding to the width of the middle or zincpile, and which notch also accommodates the screws 8 which pass throughthe outer wall E and fasten into the. 1

opposite wall A and bind the elements of the unit securely together.

The spacebetween the copper piles at the ends of the shorter zinc pileshown at D, Fig. 2, is packed with a greasy wax or other Water and acidresisting material which acts to insulate the zinc from direct action ofthe bath .solutionand protects the zinc from too rapid disintegration.-

This greasy material also protects the screws at these points and at theheads thereof, which are sunken below the surface of the wood and filledover the top with the same material, as at b Fig. 1. For this purpose Ihave found a composition of rosin four parts, petroleum jelly two parts,paraifin two parts, and sulphur flour two parts very satisfactory, butany other suit;

ployed.

.The unit, as a whole is represented in Figs. 2 and 3 by G and the bathor cell by 'H..

In operation this unit or electro-couple is immersed V in thephotographic solution or an electroable material or composition may beem-,

lyt-ic action which builds up the silver on the insulating or coveringmedium instead of on the elements of the electro-couple. Thus, theactive elements of the electrocouple are separated by the absorbent non-4. An electro-couple for reclaiming silver in solution, comprising aplural number of layers of abutting plates having insulatin materialbetween the respective layers, an

binding means uniting said plates and maconductor strips F and alsoconfined. be-' tween and covered by the wooden pieces and E,respectively, to partially insulate f; 2 elements from the solution andrestrain t action of the solution on the elements, and to build up themetal in the solution upon the surfaces directly exposed to thesolution. In this connection it should be noted that the copper andzincelements in each layer or lamination of the electro-couple areseparated by an absorbent strip F which pre- -vents the metal insolution from being deposited upon the major plane surfaces-of theelements and causes the deposition to.

take place mainly upon the insulating or resistance covering for theelements from which -it can be readily stripped and released. In thisway the silver. in the-bath is completely recovered and the bathrejuvenated or regenerated.

What I claim is: 1. The process herein described of recovering silver insolution in a photographic or like bath, consisting in subjectingthe'solu tion to the electro-chemical action of an electro-couple and inrestrainin the free action of the solution-and buil ing up a silverdeposit mainly apart from the active elements of the electro couple.

2. A medium for reclaiming silver from hyposulphite and other bathscontaining silver in solution, comprising an electrocouple and meanscontiguous to the elements thereof adapted to restrain the free actionof the solution and efiect the electrodeposition of silver in a massthereon.

3. An electro-couple for reclaiming silver from baths containing silverin solution, comprising a plurality of layers of different metals andinterjacent layers of porous material, and a covering of non-metallicmaterial.

terial tightly together.

5. An electro-couple for recovering metals in solution, comprisingabutting copper and zinc plates arranged in layers with non-conductingmaterial intervenin I said layers, and means adapted to insu ate saidzinc plates from direct contact with the solution.

6. A medium for recovering silver from baths containing silver insolution, compris- I crystalline coherent deposit upon saidelectro-couple. I

- 8. A process of recovering a metal in solution, consisting in placingan electrocouple in the solution in association with a resistance mediumadapted to receive the electro-deposition of the metal on the exposedsurfaces thereof.

9'. A process of recovering a metalin solution, consisting in efi'ectinga resistance tion of the metal. I

10. A process of recovering a metal in solution, consisting in partiallyenclosing the elements of an electro-couple within a non-' metalliccovering of low conductivity and b zween the elements of anelectro-couple in t the solution concurrently with the deposiimmersingsaid covered electro-couple within the solution until completeelectro-deposition of the metal takes place.

Signed at Cleveland, in the county of Cuyahoga, and State of Ohio, this12 day of May, 1919.

NATHANIEL B. AUKERMAN.

